Soluplus Based Polymeric Micelles and Mixed Micelles of Lornoxicam: Design, Characterization and In vivo Efficacy Studies in Rats

Aim: To investigate potential of polymer Soluplus (SP), to form micellar/mixed micellar systems and its ability to improve solubility and consequently therapeutic efficacy of model BCS Class-II drug Lornoxicam (LNX). Methods: Soluplus based micellar systems were prepared using thin film hydration method. CMC (critical micelle concentration) was determined using two methods, namely, Iodine UV spectroscopy and Pyrene fluorescence spectroscopy. Micellar systems were characterized for their particle size, drug loading, CMC and SANS study to understand the dynamics of micellar systems. The LNX loaded micellar systems were evaluated in vivo, to evaluate their effectiveness in improving the anti-inflammatory activity of LNX in rat-paw edema model and also to observe possible reduction in ulcerogenic potential of LNX. Results: SP as well as its mixed micellar systems could effectively form stable micelles with mean diameter in range of 60-70 nm and promising LNX loading efficiency. It was evident from CMC studies (using Iodine UV spectroscopy and Pyrene fluorescence spectroscopy methods) and with rubinghs regular solution theory that Soluplus could effectively form stable mixed micelles with other micelle forming agents like Solutol HS 15 (ST) and Phospholipon 90 H (PL 90H). SANS spectra confirms the presence of micellar systems and applying sphere model of SASFIT software, it was found that micelles exhibited spherical shape. In vivo anti-inflammatory study indicated that LNX loaded micellar systems resulted in superior therapeutic efficacy than LNX suspension, even at a reduced dose (p<0.05). The ulcerogenic potential of LNX was also significantly reduced when LNX was incorporated into the micellar system. Conclusion: Soluplus possessed ability to form stable micellar systems which demonstrated promising potential to improve solubilization of a BCS class II drug, LNX and improved its therapeutic efficacy with reduction in adverse effects when tested in vivo in rats.